JPS60227795A - Walking bar mechanism of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an upper feed dog drive mechanism for a sewing machine, particularly for an overcut sewing machine.

(Prior Art) Conventionally, there is a mechanism as shown in FIG. 5 as an upper feed dog drive mechanism for an overlock sewing machine.

The upper feed dog 1 is connected to a longitudinally movable arm 3 via a swing frame 2 and moves back and forth, and the vertically movable arm 4.
It moves up and down via the swing frame 2, and four movements are performed by this back and forth movement and up and down movement. A suppression spring 5 always acts on the upper surface of the swing frame 2, and presses the swing frame 2 downward so that it does not play during vertical movement.

(Problems to be Solved by the Invention) For this reason, when the upper feed dog 1 is driven at high speed, the pressing spring 5 causes jumping and the upper feed dog does not move accurately.

This invention was made by focusing on these drawbacks.
To provide an upper feed swing mechanism for a sewing machine in which a suppression splinter does not jump even when an upper feed dog is driven at high speed.

[Structure of the invention]

(Means and effects for solving the problem) This invention connects the forward and backward movable arm and the vertical movable arm to the upper feed swing frame via a link mechanism, and the upper feed swing frame is oscillated by this link mechanism. The above-mentioned drawbacks are solved by absorbing the above-mentioned pressure spring and thereby preventing the swinging of the upper feed swinging frame from being applied to the pressing spring.

(Example 1) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3.

In the figure, 10 is rotatably supported on the machine frame and swings in the vertical direction (arrow Y direction) in conjunction with a main shaft (not shown), and 11 is rotatably supported on the machine frame. It is a back-and-forth movable arm that swings in the horizontal direction (in the direction of arrow X) in conjunction with the main shaft.

Reference numeral 12 denotes a second link whose one end is rotatably supported by the forward and backward movable arm 11, and the other end is rotatably connected via a pin 13 to an upper feed dog swinging rod 15 having an upper feed dog 14 fixed to its tip. It is.

16 is a rotating arm rotatably supported on a bin 17 fixedly supported on the machine frame; 19 is rotatably supported at one end on the rotating arm 16; and the other end is attached to a second link 12. The upper feed dog swinging rod 15 and the pin 13 are rotatably supported by a pressing spring that is interposed between the right end of the rotary arm 16 and the machine frame and acts to rotate the rotary arm 16 counterclockwise. , 21 is a cushioning member made of rubber or the like fixed to the left end of the rotating arm 16. 22 is the vertically movable arm 1
This is a first link that is rotatably supported at the intermediate portion of the upper feed swing frame 15 and the upper feed swing frame 15, respectively.

(for production) Next, the present invention will be explained in detail.

In a normal feeding state, when the sewing machine is started, the longitudinally movable arm 11 and the vertically movable arm 10 swing in the directions of arrows X and Y.

The swinging motion of the back and forth arm 11 is transmitted to the upper feed swing frame 15 via the second link 12, and moves the upper feed swing frame 15 in the front and back direction. Further, the swinging of the vertically movable arm 10 moves the upper feed swinging frame 15 in the vertical direction via the first link 22. The movements of the upper feed swing frame 15 in the longitudinal direction and the vertical direction are combined to cause the upper feed dog 14 to perform four movements as shown in FIGS. 1 and 2.

At this time, the upper feed swing frame 15 swings as the second link 1
2. Third link 19. Since this is done via the first link 22, the suppression spring 20 is not displaced, and therefore problems such as jumping do not occur.

As shown in FIG. 3, even when feeding a stepped portion of cloth, if the upper feed dog 14 is located at the stepped portion of the cloth, each link 12.19.2
2 acts as the upper feed dog 14 rises, and the rise of the upper feed dog 14 does not act on the suppression spring as in the conventional case, but is absorbed by the links 12, 19, 22. The presser pressure of the teeth 14 no longer becomes abnormally high, and the cloth can be fed smoothly with an appropriate presser foot.

(Example 2) FIG. 4 shows another embodiment.

In this embodiment, the connecting member is constituted by a square piece 24 that is slidably supported on the rotating arm 16 at one end and rotatably supported on the second link 12 and the upper feed dog swinging rod 15 at the other end. be done.

In this embodiment, the sewing machine starts and the forward and backward movable arm 11.
When the vertically moving arm 10 swings, the upper feed dog swinging rod 15 moves four times, and the square piece 24 slides on the rotating arm 16. The sliding motion of the upper feed dog swinging rod 15 is absorbed by the movement of the link 12 and the square piece 24, and no load is applied to the presser spring 5 in the normal feeding state, thereby preventing jumping.

(Effects of the Invention) As described above, according to the present invention, the upper feed dog swinging rod is connected to the longitudinally movable arm 11 and the vertically movable arm 10 via the second link 12 and the first link 22, and One end is movably supported on a rotating arm rotatably supported on a frame, and the other end is movably supported on a rotating arm that is rotatably supported on a frame.
Since the connecting member rotatably supported on the link and the upper wide tooth swinging rod is provided, the swinging of the upper feed dog is absorbed by the second link connecting member and acts on the suppression spring in the normal sewing machine driving state. Since this eliminates this, it is possible to prevent the suppression spring from jumping.

[Brief explanation of drawings]

1 to 3 are front views of one embodiment of the present invention, FIG. 4 is a front view of another embodiment, and FIG. 5 is a front view of a conventional example. 10...Vertical moving arm 11...Back and forth moving arm 15...Upper feed dog swinging rod 16...Rotating arm 19.24...Connecting member 20...Press spring Applicant's name Tokyo Juuki Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] 1) A vertically movable arm rotatably supported on the machine frame and swinging in the vertical direction in conjunction with the main shaft; A front and rear movable arm that swings in the horizontal direction; an upper feed dog swinging rod whose tip is connected to the front and rear movable arm via a second link and whose intermediate portion is connected to the vertical movable arm via the first link; A rotating arm that is rotatably supported on the frame; a connecting member that connects the connecting portion of the upper feed dog swinging rod to the second link so as to be able to move approximately horizontally with respect to the rotating arm; and the rotating arm and the machine frame. The upper feed mechanism of a sewing machine consists of a pressure spring interposed in between. 2) The front %a4 connecting member is rotatably supported on the rotary arm,
The upper feed mechanism of a sewing machine according to claim 1, comprising a third link whose other end is rotatably supported by the second link and the upper feed dog swinging rod. 3) The connecting member is comprised of a square piece that is slidably supported on one end of the rotating arm and that is rotatably supported on the second link and the upper feed dog swinging rod at the other end. Upper feed mechanism of the sewing machine described.